Terminal connection for spark-plug electrodes



H. RABEZZANA TERMINAL CONNECTION FOR SPARK PLUG ELECTRODES Filed July- 26 1920 HECTOR RAIBEZZANA,-OF FLINT, MICHIGAN, ASSIGNOR TO A C SPARK. PLUG COMPANY,

OF FLINT, MICHIGAN, A CORPORATION OF-MIGHIGAN.

TNAL connncrron non s ank-rave nnncrncnns.

Application filed July 26, 1920. Serial No. 398,986

To all whom it may concern:

Be it known that I, HECTOR RABEZZANA, a subject of the King of Italy, and a resident of Flint, county of Genesee, and State of Michigan, have invented certain new and usefulIm rovements in Terminal Connections for park-Plug Electrodes, of which the following is .a full, clear, concise, and exact description, such as will enable others skilled in the art to which the invention relates to make and use the same, reference being made therein 'to the accompanying drawings, which form a part of this specification.

My invention relates to spark plugs designed for use with internal combustion engines to ignite the combustible mixture supplied" thereto, and particularly to terminal connectors associated with the inner insulated electrode of the plug and the purpose of which is. to facilitate the connection there-. with of a suitable leading in conductor through which current is supplied to the plug; the construction of the terminal in question being such that the leading in conductor may be readily disconnected from the central electrode if and when it becomes necessary to remove the lug from the opening in the engine cylin er provided for its reception, and as readily connected with the plug after it has been restored to its operative position.

The principal object of my inventiomis to provide a terminal connector for spark plugs, particularly for the inner electrode thereof, of the general type or class above referred to and in which the terminal in question may be assembled with the electrode by simply pushing the same onto a threaded or roughened end of the said electrode after which the terminal will be socurely held in place upon the electrode, altho it may be removed therefrom by unscrewing the same in th'esame manner that an ordinary nut is unscrewed from a threaded member.

Afurther object of my invention is to provide an improved terminal. for spark lugs of the eneral class or type above reerred to an which may be readily and cheaply made from a suitable blank of sheet metal by ordinary pressing, shaping, and similar methods, thus materially reducing thecost of the terminal end of the plug of which it forms a part.

A further object of my invention is to provide an improved terminal connector for spark plugs the construction of which is such that leading in conductors equipped with various types of connecting members or terminals may be used with one and the same standard form of plug and terminal connector thereof;- thereby providing a plug of standard form and construction as regards the terminal and the insulated elec-. trode thereof, but in which leading in conductors having, various styles of terminal connectors may be used; so that one form of plug may be used in connection with various ignition systems the leading in conductors of which may be equipped with connectors"varying in form one from" another.

With the above and other objects of invention in view my invention consists in the improved terminal connection for spark plug electrodes illustrated in the accom anying drawing and hereinafter describe and claimed; and in such variations and modifi cations thereof, within the scope of the coneluding claims, as will be obvious to those skilled in the art to which my invention relates. y

Referring now to the drawing whereinthe preferred embodiment of my invention is illustrated: V

Figure l is a view showing aspark plu p the central electrode of which is equippe with a connecting terminal made in ac cordance with my invention, the view being. in sideelevation. v

Figure 2 is a view upon a considerably larger scale showing a section of another form of terminal made in accordance with. my invention. Figures 3 and 4- are similar views showing other forms of terminal. I I I Figure 5 is a,view partly in section and I partly in elevation showing-a further modified form of my invention;

Referring to the drawing, the reference numeral 6 designates the external shell or casing of a spark plug within which an insulating member 7 is held in place, and which insulating member supports the central electrode 8 of the plug; the said electrode extending along a passa e which extends longitudinally of the insu ator and the. upper end thereof being ordinarily threaded as shown at 9. This threaded portion is commonly'present in sparkplugs in order the electrode extends into an interiorly,

threaded passage in the upper end of the porcelain or e uivalent insulating member and is cements in placetherein, and a nut 10 is commonly present which is screwed down onto the upper end of the insulating member 7, and is intended to remain permanently assembled with the central electrode.

The reference numeral 11 designates my improved terminal connectoras a whole, the

same being secured to the threaded projecting portion of the inner electrode in accordance with my invention and with which the end connecting element of a leading in conductor or cable is connected when the plug is in use. This terminal may vary considerably inform, Figures 1, 3 and 5 showing a form which is provided with a dome shaped or approximately spherical head 12 adapted for use with supply cable connectors having a resilient socket or resilient arms designed to be forced over the head; while Figure 4C shows'a form of my improved connector in which a neck ortion 13 is provided intermediate the eight thereof and which neck is designed to accommodate an annular resilient terminal which slips down past the large portion or head and engages the neck thereof.

Figure 2 shows a form of my invention havin an approximately spherical head like t e head 12 in-the form of my invention above referred to, and having also a projecting flange 14 beneath which and between the underside thereof and the nut 10 a forked end connector with which some forms of leading in conductors are equipped may be made to engage, the bifurcated ends of the forked connector being held in place between the flange 14 and the nut 10 as will be a preciated.

y improved terminal connector is preferab y made from a comparatively thin sheet metal blank which is shaped by means of suitable dies in such a manner as to produce the terminal of the particular form desired in each particular case. The terminal in all cases is in the form of a hollow shell, as will be appreciated, which fits down over the threaded or otherwise roughened upper end 9 of the inner electrode; the lower neck portion 15 through which the said threaded end extends, as clearly shown in the sectional views, being of greater diameter than the threaded portion and no attempt being made to secure a close fit of the threaded end within the said neck.

Formed in the peripheral wall of the terminal 11 and preferably inthe neck portion 15 thereof are one or more holding members 16,

said members being preferably arranged in airs opposite one another as shown to therey provide a balanced construction and one in which theposition of the terminal as a whole will be concentric relative to the threaded end of the elect-rode; altho it will of course be appreciated that the number of separate holding members or tongues 16 is immaterial and that three of another number of such tongues may be used when desired.

The tongues 16 are shown as formed by cutting portions of the wall of the terminal. commonly portions located in the neck portion thereof, free fromthe rest of the wall along two sides and across their tops, and bendlng the portions thus cutaway inward so as to cause their free ends to be in position to engage the threaded or otherwise roughened end of the electrode in the manner clearly illustrated in- Figures 2 to 5-of the drawing.

The tongues 16 or equivalent holding members are resilient to a considerable degree, as the material from-which the terminal as a whole is formed will ordinarily be one having a considerable degree of resilience; from which it follows that the terminal may be assembled with the plug by simply forcing the terminal and plug toward one another without imparting rotary motion to either durin which movement the threads upon the electrode and the free ends of the ton les 16 slip past one another; it being appreciated that the internal diameter of the neck does not have to correspond at all closely with the external diameter and the threaded portion of the electrode so long as the diameter in question is sufficiently large to permit the entrance of the threaded portion of the electrode between the free ends of'the tongues in question.

it will be appreciated that while the terminal maybe assembled with the plug by simply pushing the end of the electrode into the hollow terminal the free upper ends of the tongues will nevertheless prevent the terminal from being pulled straight ofi' the said threaded portion, altho the same may be removed byrotary motion in the same manner that a nut may be removed from the threaded portion of the electrode. It therefore follows that the terminal of the spark plugs made in accordance with my invention maybe assembled with the plug with expreciated that a terminal made in accordance with my invention will be very much cheaper than terminals of the form heretofore in common use and upon which various treme rapidity, and that the same will be shaping, tapping, and cutting ofi operations have to be performed, as in the case I portions of the tongue 16 are preferably parallel with one another, so that the tongues are of equal width throughout, this is a fea ture of construction which may be varied without departing from my invention; and it will also be appreciated that the shape of the upper ends of the tongues is a matter of secondary importance and that the same may be inclined so as to provide a firm seat between the extremities thereof and the threaded portion of the inner electrode, or otherwise shaped to rovide a strong holding action between t e upper ends of the said tongues and the projections on the central electrode'with which they co-operate to prevent movement of the'terminal oil from the upper end of the electrode after the ave been properly assembled. Having thus described and explained my i vention, I claim and desire to secure by tters Patent: 1. A terminal connection for spark plug electrodes comprising a hollow shell closed at one end and open at the other end and adapted to fit over a threaded end of an electrode; and a holding member integral with said shell and extending into the interior thereof; the free end of said holding member being so arranged as to slide freely over a threaded. end of the electrode in one direction and to prevent movement of said shellrelative'to said'electrode in a reverse direction.

7 2. In a terminal connector for spark plug electrodes, a hollow shell closed at one end and open at the other end and formed. from comparatively thin sheet metal and adapted to fit over the threaded end of an electrode; and a plurality of tongues out free from the wall of said shell and the free upper ends of which are forced inward and into a position to'engage the threaded end of an electrode.

'3. n a terminal connector for spark plug electrodes, a hollow shell'compr-isin a single thickness of metal throughout and s aped to provide an enlarged 'head portion, and a neck portion of reduced diameter adapted. to fit over the threaded end of .an electrode; and a plurality of oppositely located tongues out free from the .wall of the neck portion of said shell and the free ends of which are forced inward and into a position to engagethe threaded end of an electrode.

4. A terminal connector for spark plug electrodes formed from a sin le piece of sheet metal so shaped as to provide a hollow shell having a head portion, and a neck portion of reduced diameter adapted to fit over theroughened end of an electrode; and a plurality of tongues out free from the wall of said neck portion and the free'ends of which tongues are so disposed as to move freely over the roughened end of said electrode in one direction, and to prevent movement of said shell in a reverse direction.

5. A terminal connector for spark plug electrodes formed from a single piece of sheet metal so shaped as to provide a'hollow shell or casing adapted to fit over an electrode the upper end of which is provided with projecting portions, and whichconnector islprovided with a head portion, and with a neck! portion below said head, portion and of greater internal diameter than the diameter of the end of said electrode; and a pluralityof tongues cut free from the walls of the neck portion of said shell and the free inner ends of which are-adaptedto'engage said projectingportion 'to thereby hold said terminal in place. thereupon.

6, A terminal for spark plug electrodes formed from a single piece of sheet metal so shaped as to. provide a hollow shell or casing havin an enlar ed head ortion; a neck portion elow said ead portion adapted to fit over the threaded end ofan elec-' trode; a flange extending from said neck portion above the lower end thereof anda lurality. of tongues out free from the wall 0 the portion of said shell above the flange afore- 1 trode.

- .In testimony whereof I afliir m si ature.

HECTOR RAB ZZ NA. 

